Identity Federation and Attribute-based Authorization through the Globus Toolkit, Shibboleth, GridShib, and MyProxy Tom Barton 1, Jim Basney 2, Tim Freeman 1, Tom Scavo 2, Frank Siebenlist 1,3, Von Welch 2, Rachana Ananthakrishnan 3, Bill Baker 2, Monte Goode 4, Kate Keahey 1,3 1 University of Chicago 2 National Center for Supercomputing Applications, University of Illinois 3 Mathematics and Computer Science Division, Argonne National Laboratory 4 Lawrence Berkeley National Laboratory NIST PKI Workshop, April 4th 2006

Background

3NIST PKI Workshop April 4, 2006 Globus Toolkit Toolkit for Grid computing –Job submission, data movement, data management, resource management Based on Web Services and WSRF Security based on X.509 identity- and proxy-certificates –May be from conventional or on-line CAs

4NIST PKI Workshop April 4, 2006 Grid PKI Large investment in PKI at the international level for Grids –Dozens of CAs, thousands of users International Grid Trust Federation – Intended for point-in-time authentication –As opposed to, e.g., document signing Uses RFC 3820 Proxy Certificates for delegation and single-sign on Keys stored in Highest Common Technology == User’s local filesystem

5NIST PKI Workshop April 4, 2006 Shibboleth Internet2 project Standards-based (SAML) Allows for Identity Federation –Identity == Identifier + Attributes –Identifier may or may not be a persistent Name. –Allows for pseudonymity via temporary, meaningless identifiers called ‘Handles’ Allows for inter-institutional sharing of web resources (via browsers) –Provides attributes for authorization between institutions Being extended to non-web resources

6NIST PKI Workshop April 4, 2006 MyProxy The Team: –Jim Basney (lead), Bill Baker, Patrick Duda, Von Welch Many contributors –E.g. Monte Hall (LBNL) A service for managing X.509 PKI credentials –A credential repository –Long-lived private keys never leave the server Originally, a method for delegating credentials to Web Portals –Work around for lack of delegation in Web Browsers –User delegates RFC 3820 Proxy Certificate to MyProxy, Portal delegates from MyProxy Open Source Software –Included in Globus Toolkit 4.0 and CoG Kits –C, Java, Python, and Perl clients available

7NIST PKI Workshop April 4, 2006 GridShib NSF NMI project to allow the use of Shibboleth-issued attributes for authorization in NMI Grids built on the Globus Toolkit –Funded under NSF NMI program GridShib team: NCSA, U. Chicago, ANL –Tom Barton, Tim Freemon, Kate Keahey, Raj Kettimuthu, Tom Scavo, Frank Siebenlist, Von Welch Working in collaboration with the Internet2 Shibboleth Design team

8NIST PKI Workshop April 4, 2006 Common Goals of GridShib and MyProxy Ease of use for Grid PKIs X509 Credential management is a big headache for all involved –Users hate process of getting certificates –Admins hate not know where private keys are –Everyone hates configuration overhead (mainly CRLs) Both projects working to use federation combined with X509 to solve these problems Integration of Site with Grid security

Results from Past Year

10NIST PKI Workshop April 4, 2006 MyProxy Authentication MyProxy has traditionally supported: –Key Passphrase –X.509 Certificate for credential renewal In the past year, we have added: Pluggable Authentication Modules (PAM) –Kerberos password –One Time Password (OTP) –Lightweight Directory Access Protocol (LDAP) password Simple Authentication and Security Layer (SASL) –Kerberos ticket (SASL GSSAPI) PubCookie

11NIST PKI Workshop April 4, 2006 MyProxy Online Certificate Authority Issues short-lived X.509 End Entity Certificates –Leverages MyProxy authentication mechanisms –Compatible with existing MyProxy clients Ties in to site authentication and account management –Using PAM and/or Kerberos authentication –“Gridmap” file maps username to certificate subject LDAP support for mapping Avoid need for long-lived user keys Server can function as both CA and repository –Issues certificate if no credentials for user are stored When combined with pluggable authentication, allows for easy way to leverage existing authentication for X509 access –Kx509/KCA replacing Kerberos with various technologies (Implemented by Monte LBNL)

12NIST PKI Workshop April 4, 2006 MyProxy: Managing Trust Roots Based on ideas put forth in Gutmann’s plug-and-play PKI paper When user authenticates to get X509 credential, also provide needed trust information –CA certificates, CRLS, other related policy

13NIST PKI Workshop April 4, 2006 GridShib Overview Two components –GridShib handlers for Globus Toolkit (GT4) –GridShib plugin for Shibboleth (1.3) Working together they allow GT service to request Shibboleth attributes And make authz decision based on those attributes All software open source

14NIST PKI Workshop April 4, 2006 GridShib for Globus Plugin Three components Basic SAML Query Policy Information Provider (PIP) –Queries Shibboleth AA using X509 DN and retrieves user attributes –Needs GridShib for Shibboleth plugin at AA SAML identity mapper PIP determines local username from SAML attributes SAML PDP makes access control decision based on SAML attributes

15NIST PKI Workshop April 4, 2006 GT Authorization Architecture GridShib work is forming basis for rich authorization architecture in GT Configurable collection of PIPs gather attributes regarding user –SAML, X509, local, etc. –Canonicalize to XACML Request Context Configurable collection of PDPs render authorization decision –PDPs can be local or remote (GGF OGSA-Authz SAML protocol) –PDPs can be combined logically in different ways (AND or OR) –PDPs can gather own attributes (e.g. PERMIS)

16NIST PKI Workshop April 4, 2006 GridShib for Shibboleth Plugin NameMapper for Shibboleth IdP Converts X509 DN into locally meaningful name Currently uses static mapping –Already being improved on

17NIST PKI Workshop April 4, 2006 GridShib Flow: Putting it together User makes request of GT service as usual –X509 authentication with SOAP GT SAML PIP queries Shibboleth AA using DN –SAML Query protocol GridShib Namemapper converts from DN to local principal name Shibboleth AA returns SAML assertion with attributes –SAML Response protocol GT SAML PIP binds attributes to DN in GT internal state GT then maps user to local account and/or renders access control decision

Next Steps

19NIST PKI Workshop April 4, 2006 GridShib/MyProxy Integration Allow for leveraging of Shibboleth SSO for Grids –Need to convert Shibboleth SAML into X509 Accomplish by adding SAML authentication support to MyProxy –Ala Pubcookie Have implemented prototype GridShib CA –Portal authenticates user, MyProxy trusts portal to have done so and issues X509 Credential –Java Web Start application download credential from portal to user desktop Investigating full Shibboleth authentication to MyProxy –May have to wait until Shibboleth 2.x

20NIST PKI Workshop April 4, 2006 The Name Mapping Problem End-to-end flow involves both protocol and name conversion –Site, SAML, X509 Not clear that these conversions should be co-located, who should be authoritative

21NIST PKI Workshop April 4, 2006 Name Binding If site is authority for both SAML and X509 names, then they can make mappings or use algorithmic transformation Today this is often not the case –E.g. CA is run by Grid community Two options we’re exploring: User binds names by dual-authentication CA binds names when it issues a credential –Either by direct communication with Shibboleth AA Allow Shibboleth AA to recognize DN –Or by embedding information into the X509 certificate Allows resource to know Shibboleth Name Working in collaboration with Jill Gemmill, J.P. UAB (myVocs)

22NIST PKI Workshop April 4, 2006 Questions? Project URLS – – – Acknowledgements –The GridShib work is funded by the NSF National Middleware Initiative (NMI awards and ). Opinions and recommendations in this paper are those of the authors and do not necessarily reflect the views of NSF. –The MyProxy work was funded by the NSF NMI Grids Center and the NCSA NSF Core awards. The online CA work was implemented at LBNL.